When you do something and the computer doesn't seem to respond, it's real tempting to just try to do it again (click on something with the mouse, use a key combination like Ctrl-Z, etc.) a whole bunch of times to try to let the computer know you are in a hurry and you REALLY want it to do this particular task.

Unfortunately, doing the same thing over and over actually makes the computer even slower because it treats each click adds to the computer's "To Do" list.

As hard as it is to do, hit your key combination or click your mouse on something and wait. Listen for the computer accessing the hard drive, which indicates that something is going on. There is often a light that will indicate this. Particularly when you see the hard drive being accessed, don't add more demands on the computer.

It may be that your clicks "didn't take" which sometimes happens. After you have waited, try again, being sure that you have centered your mouse cursor over the area where you want to click--watch to see if the arrow changes into a hand and that will tell you that you can click. In the case of keyboard commands, make sure you are making them correctly--holding down Control/Alt/Shift as the program requires before hitting whatever other key you need to hit). You might want to click twice if you have tried clicking once, waited, and then clicked one more time and waited. All this takes time, but by waiting, you will learn about how the program processes your command and you will learn how things work. Later you won't have to wait because you'll know what is going on.